STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME/(LOSS) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net income	$ 25,915	$ 62,303	$ 10,968
Foreign currency translation adjustments:
Unrealized net change arising during the period	4,813	4,066	(7,501)
Comprehensive income/(loss)	41,044	59,799	(8,727)
Foreign Currency Forward Contracts [Member]
Derivatives and Hedging instruments [Abstract]
Unrealized net (loss)/gain	0	(51)	624
Reclassification adjustments for (gains)/losses included in net income	0	(329)	(143)
Income taxes	0	110	(142)
Interest Rate Swap Agreement [Member]
Derivatives and Hedging instruments [Abstract]
Unrealized net (loss)/gain	(130)	(1,253)	0
Reclassification adjustments for (gains)/losses included in net income	444	323	0
Income taxes	(110)	326	0
Pension Plans [Member]
Actuarial gain/loss [Abstract]
Actuarial gain/(loss) arising during the period	13,651	(4,413)	(14,126)
Amortization to net income of net actuarial loss	1,339	1,140	618
Prior service cost [Abstract]
Amortization to net income of net prior service cost	50	110	486
Other Comprehensive (Income) Loss, Pension and other Postretirement Benefit Plans, Tax [Abstract]
Income taxes	$ (4,928)	$ (2,533)	$ 489